Recipe: Simple Beef Fajitas

Adapted from The Cook's Illustrated Cookbook, 2011, page 497 and appearing in Cook's Illustrated in February 2007 as "Gas-Grilled Beef Fajitas". Prepared for dinner on Sunday, September 9, 2012.  Makes approximately 5 fajitas.

Cook's Illustrated recommends buying the thinnest tortillas you can find as thick ones tend to taste doughy. While at the store, compare the number of tortillas in each package with the package's weight to determine which tortillas are the thinnest. You can use any color bell peppers in this recipe but I try to choose two different colors to improve the dish's appearance.

Ingredients

2-2½ pounds flank steak
¼ cup lime juice
Kosher salt and black pepper
1 large red onion
2 large bell peppers
6-inch flour tortillas

Instructions

1.  Peel the onion and cut it into ½ inch slices.
2. Cut the bell peppers into quarters (cut through the stem and blossom end of the pepper) and remove the stem and seeds.
3. The steak will be cooked over direct heat on your grill. For a gas grill: clean the cooking grate, light the burners, turn to high, close the cover, and heat for 15 minutes.
4. Use paper towels to pat the steak dry and season both sides with lime juice, salt, and pepper.
5. Place the steak on the grill and cook until the first side is well  browned, about 5 minutes.
6. Turn the steak over and cook until the meat reaches an internal temperature of 125° (for medium rare).
7. Remove the steak from grill and let it rest on a cutting board, loosely covered with foil, for 10 minutes
8. While the steak rests, place the onion slices and bell pepper quarters (skin side down) on the grill and cook until tender and charred. Flip the vegetables every three minutes. 
9. Slice the beef across the grain into ¼-inch slices.
10. Separate the onion slices into rings and cut the pepper quarters into ¼-inch strips.
11. Gently warm the tortillas on the grill.
12. Serve, placing steak and vegetables on a tortilla and rolling it. (No, I never have learned how to do that well.)

A red onion is peeled and sliced and the bell peppers cleaned and quartered.

Grill the flank steak over direct heat until medium-rare.

While the steak rests, grill the vegetables until tender.

Slice the meat and peppers ¼-inch thick and separate the onion rings., then roll up in thin flour tortillas.